The number of shape functions in radial direction associated with this infinite element. Either way, if the modes are stored as nodal dofs (n_dofs_at_node) or as element dofs (n_dofs_per_elem), in each case we have the same number of modes in radial direction.

Note

For the case of 1D infinite elements, in the base the dof-per-node scheme is used.

From the formulation of the infinite elements, we have 1 mode, when o_radial=CONST. Therefore, we have a total of o_radial+1 modes in radial direction.